Critical Thinking and Exploratory Response: Mechanisms for
Identifying, Analyzing, and
Resolving Anomalies Safely – Case Study: Recent Shuttle Reinforced
Carbon-Carbon (RCC) Wing Leading Edge Anomalies
Dr. Charles Camarda, Astronaut & Deputy-Director for Advanced
Projects,
NASA Engineering and Safety Center
An anomaly in the Space Shuttle reinforced carbon-carbon (RCC)
wing leading edges post Columbia was recently noticed post flight of
Space Transportation (STS-114), the return-to-flight mission.
Non-destructive and destructive investigations were conducted and it
was found that a 0.5 in. wide by over 30.0 in. long region along the
upper and lower slip-side edge of RCC panel 8R had suffered severe
SiC-coating degradation, rendering the panel unusable. This
presentation will step through the process of how this anomaly was
initially overlooked;
identified and classified as a one-time event and not a safety of
flight issue; and finally
recognized by the NASA Engineering and Safety Center NESC as a
systemic hardware problem which is currently being worked by NESC
and the Space Shuttle Program. Critical thinking was necessary to
question prior, accepted results and conclusions to finally
determine that flight rationale for all Shuttle missions post
STS-114 was inadequate. In addition, the capability of analytical
methods in predicting burn-through was not fully demonstrated and
erroneously thought to be conservative. Use of an “exploratory
response” is recommended as an approach to effectively identify
critical anomalies to program management in order to illicit an
expeditious response and help prevent accidents.
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Metamaterials: Microwave to IR
Mr. Max Alexander, AFRL
Metamaterials are materials with an engineered “effective”
permittivity and permeability which do not occur naturally. The
primary focus of the discussion will be on a specific class of
metamaterials where the permittivity and permeability are
simultaneously negative over a discrete bandwidth. Under these
conditions it is possible then to form imaging elements which
display a negative refractive index in the far field. These
materials were first fabricated for applications in the microwave
but have more recently been explored in the infrared. We will discuss
the major technical milestones necessary to achieve these material
properties, the leading research in the field, and some of the
potential industrial payoffs for this technology including compact
imaging optics and improved RF components.
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Lessons Learned from the CEV TPS ADP
Dr. James Reuther, NASA ARC
NASA established the Crew Exploration Vehicle (CEV - Orion)
Thermal Protection System (TPS) Advanced Development Project (ADP)
in late 2005 as a three year effort to mitigate risks associated
with developing a lunar-return capable heat shield and provide the
preliminary designs for two heat shield systems by vehicle PDR. In
contrast to the Low Earth Orbit (LEO) return missions and re-usable
TPS employed by the Space Shuttle, the extreme heating levels for
CEV during lunar return missions, combined with its mass
restrictions, necessitates the use of ablative TPS materials for its
heat shield. Nearly 40-years of relative inactivity (since Apollo)
within NASA and industry on mid-density ablative TPS materials and
integrated heat shield systems forced NASA to engage in a heat
shield Advanced Development Effort. Unlike a traditional vehicle
development project, where choices are made between available
technologies, the TPS ADP invested simultaneously in several
competing low TRL (3-4) TPS
materials and heat shield architectures. Yet unlike a traditional
technology development project, the TPS ADP was constrained to meet
hard schedule and cost driven deliverables on the critical path for
the larger CEV Project. The scope of the TPS ADP included
significant design, development, testing, and analysis activities
spanning facilities, manufacturing, and resources distributed across
the entire country. To meet the overall challenge, the TPS ADP
established a disciplined programmatic structure to enable a
rigorous competitive TPS materials and heat shield systems risk
reduction effort, while maintaining close reporting to the CEV
Project office at JSC, and deliver heat shield design products on
schedule within the allocated budget. Although the TPS ADP was led
out of NASA Ames Research Center, it leveraged the strengths and
expertise from 8 NASA field Centers, forming a truly geographically
distributed team. Additionally, the TPS ADP managed several
competing industrial TPS contractors and worked closely with the
Orion Prime Contractor (Lockheed Martin) to ensure a tight
integration of the final products. While the overall success of the
Advanced Development Project may be measured by its direct successes
to date, it is important to consider the overall TPS ADP effort,
from conception to implementation, with a perspective toward lessons
learned and the success of future efforts. Obviously, as with any
project, some things went more according to plan than other things.
All aspects of the TPS ADP will be presented including: original
plans, current status, successes, failures, and key perspectives for
future projects. Finally, an overall future status of TPS materials
and entry systems technology status will be discussed.
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Nuclear Power Material Challenges for the Lunar Base
Dr. Michael Houts, NASA MSFC
The current focus of NASA’s space fission effort is Fission
Surface Power (FSP). FSP systems could be used to provide power
anytime, anywhere on the surface of the Moon or Mars. FSP systems
could be used at locations away from the lunar poles or in
permanently shaded regions, with no performance penalty. A potential
reference 40 kWe option has been devised that is cost-competitive
with alternatives while providing more power for less mass. The
potential reference system is readily extensible for use on Mars. At
Mars the system could be capable of operating through global dust
storms and providing year-round power at any Martian latitude.To
ensure affordability, the potential near-term, 40 kWe reference
concept is designed to use only well established materials and
fuels. However, if various materials challenges could be overcome,
extremely high performance fission systems could be devised. These
include high power, low mass fission surface power systems; in-space
systems with high specific power; and high performance nuclear
thermal propulsion systems. This tutorial will provide a brief
overview of space fission systems and will focus on materials
challenges that if resolved, could help enable advanced exploration
and utilization of the solar system.
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Aerospace Development – Reality and Dreams
Mr. Steve Ishmael, NASA (retired)
This tutorial will provide the author’s general observations,
facts, personal lessons, and experiences with 5 programs: SR-71,
NASP X-30, X-43, X-33, and the current NASA CEV. An emphasis on how
the fundamental understanding of relevant physics, capability to
actually build enabling materials/structures, and realities of
operating in the real world challenged achieving success in these
programs. The tutorial will suggest how difficult, yet deeply
satisfying participating in aerospace development is.
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Revealing the Hidden Secrets of Materials with Neutrons
Dr. Ken Herwig, Oak Ridge National Laboratory
How can one look inside ‘”thick” materials to reveal their
morphology? How can one directly measure the strain field inside
materials while they are under load, or the residual strains
produced by manufacturing processes? How can one observe in-situ the
evolution of grain structure, crystal growth, or other morphology
during materials processing? The answer – use neutrons! Neutron
scattering is an extremely powerful technique for interrogating the
structure, morphology, and magnetic properties of matter. Neutrons
are highly penetrating and can interrogate materials many
centimeters thick, revealing features at length scales ranging from
sub-Angstrom to a micron, for a wide variety of materials. Practical
applications include residual stress measurement in materials and
structures; characterization of crystalline structure and/or
molecular orientation; observation of evolving morphology and strain
states
during materials synthesis and/or processing; characterization of
the magnetic structure in magnetic materials; and 3D mapping of the
presence or absence of many liquids in materials, components, and
systems. This tutorial will describe several practical applications
of neutron
scattering for materials development and application, overview some
of the interrogation techniques, and tell attendees how and where to
obtain access to neutron characterization capabilities.
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Airborne Lasers (ABL)
Mr. James Augustine, Schafer Corporation
The Airborne Laser (ABL) is being developed as an integral part
of the Ballistic Missile Defense System designed to protect the
United States, its allies, and its deployed troops from a ballistic
missile attack. Using two solid state lasers and a megawatt-class
Chemical Oxygen Iodine Laser (COIL) housed aboard a modified Boeing
747-400 Freighter, the ABL’s mission is to detect, track, target,
and destroy ballistic missiles shortly after launch during the
boost-phase. Its revolutionary use of directed energy makes it
unique among the United States’ airborne weapon systems, with a
potential to attack multiple targets at the speed of light with a
range of hundreds of kilometers.
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Stardust
Dr. Dean Kontinos, NASA ARC
In the early morning of January 15, 2006, the Stardust Sample
Return Capsule (SRC) successfully delivered its precious cargo of
cometary ejecta particles to the awaiting recovery team at the Utah
Test and Training Range (UTTR). The SRC returned to Earth at 12.8
km/s (inertial): the fastest humanmade object to traverse our
atmosphere and only the second super-orbital velocity entry since
the Apollo Program (the previous being the Genesis SRC). The thermal
protection system (TPS) was the first use of Phenolic Impregnated
Carbon Ablator (PICA) forebody heatshield material – a NASA
developed lightweight material that manages the incident heat flux
by means of ablation. In the intervening time between the launch and
return of Stardust, NASA began the Exploration Program with a goal
of returning humans to the moon. An element of that architecture is
a Crew Exploration Vehicle (CEV or so-called Orion spacecraft) that
is to reenter the earth’s atmosphere at super-orbital velocity from
a trans-lunar trajectory. Of utmost importance is an evaluation of
the Stardust PICA forebody heatshield material as that is a leading
choice for a lunar-return-capable CEV. Unfortunately, the SRC was
not instrumented and, therefore, there are no time-resolved direct
measurements of the state of the aeroshell, e.g. acceleration,
temperature, pressure, etc. However, an auxiliary mission to observe
the entry from an airborne platform was successfully executed. These
data, in combination with preflight specifications, in-space
navigation, terminal descent radar, and recovered hardware,
constitute a rich source of evidence with which to assess the
performance of the entry system and heatshield. An overview of the
post-flight analysis will be presented along with a description of
residual uncertainties owing to the fact that the SRC was not
specifically flown and instrumented as a flight experiment.
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Manufacturing Problem/Prevention Program (MP3)
Dr. Russell Lipeles, Aerospace Corp
The MP3 meeting enables an exchange of information between the
Air Force and the contractor community on ways to prevent problems
and minimize schedule and cost impacts on space programs. The
primary emphasis is on lessons learned in the materials, processing,
and manufacturing of launch and space vehicles and related
components. MP3 topics also include advanced materials and how they
can enable future applications. Advanced non-destructive testing
methods are also MP3 topics because they relate directly to flaw
characterization that contributes to hardware quality and
reliability. In this presentation, a brief history of MP3 will be
described. Some MP3 topics from previous meetings will be summarized
including process improvements, non-destructive testing, and
advanced materials
development. Topics and plans will be presented for the next meeting
in October 2008.
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Corrosion Prevention & Control
Mr. Steven Carr, AMCOM
The Aviation and Missile Command (AMCOM) has established the
Corrosion Prevention and Control Program for its aviation and
missile weapons systems. The AMCOM Corrosion Program is managed in
the Aviation and Missile Research Development Center (AMRDEC). The
overarching focus of the program is “To Get New Technologies into
the Hands of the War-Fighter”. The Program Office has been
successful leveraging from partnerships formed with sister services
to transition new and improved corrosion prevention and control
technologies into the life cycle management for Army Aviation and
missile weapons systems. The Program Office provides near-term
solutions and implementation of new technologies to impact corrosion
at high cost locations by providing corrosion assistance to fielded
Army Aviation and Missile organizations in world-wide locations. The
tutorial will review the AMCOM Corrosion Program including corrosion
awareness, detection, identification, remediation, and preventive
maintenance measures.
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Cost Effective Missile
structures from optimum Materials and Manufacturing Processes
Dr. Ramesh Sharma, Raytheon Missile Systems
With diminishing budgets, the Department of Defense (DoD) is
facing a significant affordability issue. As responsible business
entities, DoD manufacturers must do everything in their power to
manufacture their hardware in the most cost effective manner.
Robust designs and well controlled manufacturing processes certainly
help. Selection of optimum materials and manufacturing processes,
however, offers a complementary approach for enhanced reliability
and affordability.
This tutorial will briefly review the selection process for
materials and manufacturing processes. It is important to realize
that the selection processes has to happen at the conceptual level.
Changes at any later stage become more expensive if not almost
impossible. There will be several case studies indicating the extent
of cost savings just through the selection of optimum materials and
manufacturing processes.
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The Evolution of the Mars
Science Laboratory Heatshield
Ms. Robin Beck, NASA AMES
The Mars Science Laboratory (MSL) Rover will be the largest
delivered payload to Mars. Roughly the size of a Mini Cooper, it
will require an elaborate Entry, Descent, and Landing (EDL) System.
The entry vehicle will have a diameter 4.5m. The first defense will
be the Thermal Protection System (TPS) on the heatshield which will
see turbulent heating while traveling at velocities from 5.6km/s
down to parachute deployment at approximately 2km/s. The first
approach to the TPS was found to be flawed after extensive testing,
so 23 months before launch, the TPS is going through a fast-paced
redesign.
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